The invention is directed generally to wastewater treatment systems, and more particularly, to water clarification systems using gravity.
Water treatment and wastewater treatment often includes numerous steps performed by different components depending on the contaminants to be removed. Many treatment systems include one or more systems for removing suspended solids from a fluid. One such system for removing solids is a water clarification system. Conventional water clarification systems remove suspended solids from a fluid using gravity by pumping the fluid into the bottom of a tank. The fluid fills the tank and passes over a weir located at the top of the tank. While the fluid remains in the tank, the fluid is not subjected to mechanical agitation and the suspended solids are allowed to settle out of the fluid. The solids collect at the bottom of the tank and the fluid having few suspended solids flow over a weir, through an exit channel, and into another system.
One particular water clarification system, as shown in FIG. 1, includes a plurality of plates that are generally parallel, spaced about 2 inches apart, and positioned at angles relative to a bottom floor. The plates are positioned in the system using guides attached to the side walls of the system. Water enters the system through an inlet flume near the bottom of the settling plates and passes into the space between the plates. Water flows upwardly through the space between adjacent settling plates. Suspended solids settle out of the water, collect on top surfaces of the plates, and flow down the surface of the plates, eventually falling to the bottom of the tank. Clarified water flows out of the top opening of the settling plates, over a weir and into an outlet trough.
This system is typically assembled on-site, and the tank is typically made of concrete. After the tank is formed, the plate support structure is assembled and the settling plates are installed. While this system performs adequately, it is costly to erect and difficult to assemble so that leakage does not occur around the settling plates thus bypassing the clarifier system. Water clarifier systems often require occasional routine cleaning and maintenance of the settling plates, which can be difficult and expensive.
Thus, an efficient, inexpensive, and easily maintainable water clarification system is needed.
This invention is directed to a water clarification system for removing suspended solids from liquids using gravity. The water clarification system is one component of a conventional water treatment system that may include various additional treatment steps. The water clarification system of this invention includes a housing that may have a plurality of side walls and end walls. A frame may support the side walls, end walls, and other components of the water clarification system. The water clarification system also includes a plurality of inclined settling plates. The settling plates direct the water to be clarified from an inlet distribution orifice, which may be located near the bottom of the settling plates, to an exit channel formed by top flanges of the settling plates. The settling plates are formed from a body and a top flange. The top flanges are substantially horizontal and, when several are assembled in the water clarification system, form a substantially smooth, horizontal exit channel. Each top flange contains at least one aperture for allowing clarified water to pass from the spaces between the settling plates to the exit channel.
The settling plates may be positioned in the water clarification system using a plurality of guides coupled to the side walls of the housing. In one embodiment, these guides are angle brackets attached to the side walls and may extend the entire length of the plates. Each plate may be supported by two guides, one on either side. The guides substantially seal the plates to the side walls, thereby preventing a significant amount of liquids from bypassing the inclined plates and passing through the system without clarification. In addition, the plates may be made narrower than the distance between the side walls to enable ease of installation and removal during assembly and routine cleaning and maintenance of the system.
A top flange of the settling plates may also include a sealing member for sealing adjacent plates together. In one embodiment, the sealing member is attached to the top flange. The sealing member may be angled relative to the top flange and positioned generally parallel to the body of the settling plate so that the top flange forms a seal between adjacent settling plates. The sealing member prevents liquid from leaving the space between the settling plates and entering the exit channel without first passing through the apertures in the top flange. A stiffening section, which may be substantially vertical when placed in the system, may be included in the bottom section of a settling plate to stiffen the plates.
The water clarification system may also include one or more flanges for keeping the settling plates in position. In one embodiment, the flanges may be angle brackets that may have a length sufficient to seal the edges of the flanges on the settling plates to the side walls. The flanges may be releasably coupled to the side walls for easy removal. The substantially horizontal top flanges on the settling plates enable the settling plates to be sealed to the side walls.
In one embodiment, the top flanges of the plates are made of a material having sufficient strength and shape to support the weight of maintenance personnel during routine cleaning and repair of the system.
An object of this invention is to provide a water clarification system having settling plates that are easy to be removed individually during routine maintenance.
Another object of this invention is to provide a water clarification system having settling plates that provide a support surface capable of safely supporting personnel during routine maintenance.
An advantage of this water clarification system is that the horizontal top flanges, when assembled in the system, create a smooth exit channel for the clarified liquid, eliminating the need for a separate channel.
Another advantage of this water clarification system is that the apertures located in the horizontal top flanges provide adjustable, uniform liquid flow distribution across the plurality of settling plates, thus eliminating the need for additional outlet flow distribution devices such as weirs or flumes.
Yet another advantage of this invention is that the side guides and top sealing flanges provide an effective seal to prevent liquid from bypassing the settling plates and passing through the system without first being clarified.
These and other features and advantages of the present invention will become apparent after review of the following drawings and detailed description of the disclosed embodiments.